This invention relates generally to a thermocouple testing device, and, more particularly, to an automated multiple thermocouple testing device that checks for short and open circuits. This device can be used to test thermocouple circuits in gas turbine engines.
In one possible application, multiple temperature probes are used to measure gas temperatures at various points throughout gas turbine engines such as in the combustion chamber and the inlet. Each probe may have a plurality of thermocouples therein for purposes such as redundancy in case of failure and the leads from these thermocouples may terminate in one location facilitating connection to a testing device that can indicate failure of one or more thermocouples, but in some cases, thermocouple leads may terminate at different locations making connection difficult or trouble shooting impossible. For example, the F100 fan turbine engine has two thermocouples in each probe in the fan turbine inlet temperature (FTIT) system. One thermocouple terminates in the cockpit area of the aircraft to indicate high temperature and the other thermocouple terminates in the engine electronic control area. Conventional trouble shooting procedures require that the engine is removed from the aircraft to be able to check the engine electronic control thermocouple circuits for short and open circuits. This procedure is clearly expensive and very time consuming. Thus there exists a need for a multiple thermocouple testing device that measures short and open circuits on a plurality of parallel connected thermocouples.